package exception01;

/**
 *  什么是异常(不正常)?
 *    程序在运行过程中会遇到各种各样的问题 => 异常
 */
public class ExceptionDemo01 {
    public static void main(String[] args) {
        int[] arr = null;
        System.out.println(arr.length);//java.lang.NullPointerException: Cannot read the array length because "arr" is null
    }
}
